[Characterization and calcitonin secretion of a human well differentiated C-cell tumor cell line].

Useful cell lines actively producing hormone (s) have been rare, especially those of human origin. A C-cell tumor human cell line abundantly producing calcitonin and related hormones, TT-cell, has proved remarkably useful for the study of endocrine tumors as their representative model. We proved intracellular presence of translation and transcript products of calcitonin and calcitonin gene related peptide gene by immunostain, radioimmunoassay, immunoelectron microscopy, Northern blot and in situ hybridization. We also demonstrated remarkably enhanced secretion of the hormones and chromogranins by the stimulation of protein kinase activators such as phorbol ester, forskolin, and calcium-ionophore.